Chassis for XY stage?

[TheKackler]

I am thinking to build a custom laser. I am an EE, I have built "The Book Machine" at buildyourcnc.com and I own a laser cutter so I am basically familiar with things. How do you guys get a chassis for custom lasers? I like the XY stages on the site here but what to put them in?

thanks,
-John

[twosoc]

Hey John, I built mine out of 18mm mdf. Works a treat if you make sure the table underneath is level

[Tech_Marco]

John:

Just let you know that we're working on custom made chassis with extrusion aluminum bar. It would be a in KIT format. We're going to make 3 different size: 600x400, 900x600, and 1200x900. It will be frame only, no panel included. The time frame is about 2 months

I'll ask my tech to take some pictures of the prototype and post it to the forum. With the chassis kit, it save your folks a lot of effort and more cost effective. And, it is fun to build!


Marco

[TheKackler]

Thanks Marco!

I am researching 4' wide laser cutters. I want to feed 8' x 4' sheets into it. I am evaluating dual head laser also.

-John

[Tech_Marco]

John:

For that size 8' x 4', I recommend to use "Riding tube" XY stage instead. It save laser power and power is more stable during traveling. Remember that laser beam lost power non-linear so the longer it traveled, the more power got lost. For example, you may be able to cut 8mm on location (50,50), but you may only cut 4mm or worst in (1200,1000) location. To offset this, you may want to install a beam expander. Or, use the "ride on" means that a laser tube is installed on top of the X gantry ,so as the laser power supply. That way, regardless how far it go, the light beam distance is still within certain limit.

I just have a customer ready to buy a set of that system and make his 2000mm x 4000mm machine.

Though that you may be interested


Marco

[Tech_Marco]

See 2M*4M tube riding XY stage. The max size using "Y-wheel" is 4m*4m (157.5" x 157.5")
Two Y motor (86 series) is required

Marco

[DwightMann]

Please excuse my ignorance, I am VERY new to this.

I too would like a system that can handle a 4x8 sheet of plywood, and am working on the design portion of a DIY CNC Router. I think that I have a good handle of what would be required for the router, but am rather clueless with Laser. I would like to build something that I could remove the router portion and replace with a laser when needed. With this in mind, I would like to keep as much of the router compatible with the needs for the laser.

When using the "riding tube" am I correct in assuming that the tube moves with the gantry?
Are the special considerations regarding the acceleration forced?

And more importantly, is this feasible? And is it "over my head"? I am able to follow complicated instructions and basic electronics knowledge.

[Tech_Marco]

DwightMann:

Yes, the tube is riding on the gantry and may be with the power supply as well. This stage is desgined for 'cutting' so speed isn't really matter as X can still "flying" like a regular XY stage. The Y axis is driven by two "86" stepping motors (much bigger than a 57 series). Engraving is OK but not to expect as fast as a small XY machine. Remember that the X is much faster than Y when doing engraving. And for the cutting, most job are running at 10mm~20mm/s at most.

The biggest issue is the "Shipping". This stage is 2M*4M = 6.6ft * 13.2ft. Most carrier refused to handle item over 2M long and they charge 'over size' quite a bit. I have ordered two of this system but it will ship to my by ocean freight. A customer just order the same system but I have to make it smaller 1m*1m and he will 'reb-build' it once he received it in this country. I have to provide him a diagram so he can make it up himself

If you have a big router then it is not difficult to convert it to a laser cutter. You may want to install the laser tube on the gantry provide that if the gantry is strong enough to drive the laser tube. One of my customer sent me a picture of his CNC-Laser machine with a 60W laser install 'vertically' to the gantry. Of course, it id dedicated for low speed cutting only. The tube was standing on top of the ganry so you look at the picture, you would feel 'Wow!' By the way, doing this way he saved two mirrors. Plus, power is more stable and concentrated than having a laser beam travelling in both X & Y distance. So, a 60W seems stronger than a standard machine and it does better cutting for acrylic or wood.


Marco